The structure and immunologic reactivity of colonic mucins will be studied to determine the potential of these glycoproteins as markers of colonic tissue and colonic carcinoma in particular. Specimens of colonic tissue (normal and neoplastic will be procured and characterized by histologic type. Mucins A and B will be isolated from each tissue specimen and characterized as to amino acid and carbohydrate compostion. The structure of the carbohydrate and protein portions of these mucins will be examined. Oligosaccharides and glycopeptides will be prepared, isolated and characterized as to their composition, primary structure, and immunologic reactivity. An additional portion of each mucin will be stripped of carbohydrate, in order to obtain the protein core. Lower molecular weight peptides will be prepared and examined by peptide mapping. Antisera directed against the mucins will be prepared in rabbits and the specific antibody purified by absorption and affinity procedures. The specificity of the antisera will be analyzed by a retrospective studying of biopsy specimens from individuals with benign and malignant disorders of both colonic and extracolonic tissues. The antisera will be employed in a study of the immunohisto-chemical localization of mucins for staging and prognosis in colon cancer. A sensitive radioimmunoassay (and/or ELISA) will be developed and employed in an examination of the potential role of mucins in detection, diagnosis, staging, prognosis and management of colon cancer.